Eunsu Jang

The flexible induction cooktop, which can provide an unlimited cooking area, utilizes a cost-effective method in which one inverter shares multiple working coils. However, this method has resulted in consumer needs such as reducing both the initial pot detection time and the noise caused by the relay operation. This article presents a hardware implementation and control method for a flexible induction cooktop with multiple GaN-HEMT-based inverter systems. As one way to meet consumer needs, this implementation method does not require a relay and offers the advantage of real-time pot detection and noise minimization. However, the inverter design should include the magnetic coupling effect while maintaining high performance and high power density. This article proposes an inverter design method considering the limited space and an implementation method that minimizes the effect of magnetic coupling without an additional power stage. The feasibility of the proposed implementation method is evaluated based on the results of a heating test with a 3.3 kW prototype.

In this study, wafer cleaning equipment was designed and fabricated using the induction heating (IH) method and a short-time superheated steam (SHS) generation process. To prevent problems arising from the presence of particulate matter in the fluid flow region, pure grade 2 titanium (Ti) R50400 was used in the wafer cleaning equipment for heating objects via induction. The Ti load was designed and manufactured with a specific shape, along with the resonant network, to efficiently generate high-temperature steam by increasing the residence time of the fluid in the heating object. The IH performance of various shapes of heating objects made of Ti was analyzed and the results were compared. In addition, the heat capacity required to generate SHS was mathematically calculated and analyzed. The SHS heating performance was verified by conducting experiments using the designed 2.2 kW wafer cleaning equipment. The performance of the proposed pure Ti-based SHS generation system was found to be satisfactory, and SHS with a temperature higher than 200 °C was generated within 10 s using this system.

Typical domestic induction cooktops can only heat ferromagnetic pots/vessels. However, to increase the availability and marketability of induction heating (IH) cooktop products, heating techniques for all types of metallic pots (i.e., created from metals such as aluminum, copper, and stainless steel) are required. To satisfy the requirements of induction cooktops, this paper proposes the design of an all-metal domestic IH system that can heat any type of metallic pot while considering the temperature variation of the working-coil. A control algorithm using a power curve-fitting method (CFM) is presented to quickly respond to load parameter variations in the IH. In addition, the CFM control algorithm is established to compensate for the power reference value by reflecting the increase in the working-coil temperature during the heating of the non-ferromagnetic pot. To evaluate the performance of the proposed system, the control algorithm strategy and experimental results based on a 3.2 kW all-metal IH cooktop are presented.

In this paper, a control method for the power conversion system (PCS) of plasma generators connected with a plasma chamber has been presented. The PCS generates the plasma by applying a high magnitude and high frequency voltage to the injected gasses, in the chamber. With regards to the PCS, the injected gases in the chamber could be equivalent to the resistive impedance, and the equivalent impedance had a wide variable range, according to the gas pressure, amount of injected gases and the ignition state of gases in the chamber. In other words, the PCS for plasma generators should operate over a wide load range. Therefore, a control method of the PCS for plasma generators, has been proposed, to ensure stable and efficient operation in a wide load range. In addition, the validity of the proposed control method was verified by simulation and experimental results, based on an actual plasma chamber.